Mandrel assembly for air filter apparatus

ABSTRACT

An automatic air filter and more particularly an automatic air filter of the type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage to clean dirty air as it passes through such passage.

United States Patent [1 1 Welch et al.

[ MANDREL ASSEMBLY FOR AIR FILTER APPARATUS [75] Inventors: Wilson A. Welch; Alan E. Revell,

both of Louisville, Ky.

[73] Assignee: American Air Filter Company, Inc.,

Louisville, Ky.

22 Filed: Jan. 28, 1972 21 Appl. No.: 221,550

[56] References Cited UNITED STATES PATENTS Kenworthy 242/68.1

........... B0ld 46/22 Nov. 27, 1973 1,919,769 7/1933 Brown et al. 242/68.6 2,267,126 12/1941 Morretti 113/116 D 2,977,060 3/1961 Beming et al. 242/68.6 X 3,280,539 10/1966 Parrott 55/354 3,291,413 12/1966 Cushing et al. 242/68.6 3,552,101 1/1971 Papp 55/354 3,557,946 l/l971 Sviokla 242/55.55 X

749,971 1/1904 Nordhoff 242/74.2 X

794,494 7/1905 Foster 242/74.1 1,095,723 3/1913 Frisoli 242/74 Primary ExaminerDennis E. Talbert, Jr. Assistant Examiner-Neil F. Greenblum Att0mey-Robert W. Fletcher et al.

57 ABSTRACT An automatic air filter and more particularly an automatic air filter of the type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage to clean dirty air as it passes through such passage.

4 Claims, 8 Drawing Figures Patented Nov. 27, 1973 3 Sheets-Sheet 1 Patented Nov. 27, 1973 3.774.373

l5 Sheets-Sheet Patented Nov. 27, 1973 1 3,774,373

3 Sheets-Sheet 3 MANDREL ASSEMBLY FOR AIR FILTER APPARATUS BACKGROUND OF THE INVENTION The present invention finds particular applicability in those air filters known in the art wherein a supply of filter media, furnished on a roll mounted in a supply zone at one end of the filter, is withdrawn from the roll and moved through an air cleaning zone for air cleaning purposes and is finally directed into a discharge or rewind zone at the opposite end of the filter where it is manipulated into a roll package for disposal. It is to be understood that the present invention is not to be considered as limited to a specific filter medium or structure, but that it can be utilized in any one of a number of known filter structures wherein any one of a number of known types of filter medium in roll form is progres sively advanced across an air stream passage to clean air as it passes through the passage.

In the prior art various types of spindle arrangements have been utilized in the rewind zone of the aforedescribed filter arrangements to support the cores on which rolls of filter medium materials are manipulated into compact packages for disposal. These spindle arrangements, many of which have end plates to align the used filter media when rewound, for the most part have been cumbersome and complex to construct and maintain and have been limited in use. The present invention provides a spindle arrangement which can be utilized in the rewind zone, and, more-specifically, pro-' vides a mandrel assembly for fastening end plates to a tubular core to fabricate a spindle, which permits simple efficient manipulation of used filter media into a roll package for disposal. In addition, the arrangement of the present invention is a straightforward, inexpensive readily constructed and easily maintained spindle which can be readily converted to use in the supply zone, if and when the occasion arises.

SUMMARY OF THE INVENTION More particularly the present invention provides an air cleaning device of a type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage from a supply zone to a rewind zone, with an improved spindle assembly for supporting and rewinding contaminantloaded media into a roll, said spindle assembly comprisa substantially rigid longitudinally extending hollow core of generally circular cross-section to provide a support upon which said web may be rewound; said core being arranged to extend transversely across said air cleaning device;

a web fastening means to secure the web end on said core;

end plates, at each end of said core, each having a slot means therein opposedly positioned across from each other to secure said web fastening means adjacent to said core; v

irregularly shaped mandrels inserted in each end of said core to securely fasten said end plates to said core and provide coupling meansby which said spindle may be rotated.

The present invention has been found to be an expedient method of providing for the rewinding of used filter media, which allows a minimum of effort to be employed, and provides a minimum number of steps in changing the mediasupply, as well as guaranteeing positive rewinding of the media.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an'elevational perspective view of a vertically disposed filter arrangement including the invention of this disclosure;

FIG. 2 is an enlarged perspective view showing the novel rewind spindle apparatus;

FIG. 3 is a top view of the mandrel shown in FIG. 2;

FIG. 4 is a side or longitudinal view of the mandrel of FIG. 3;

FIG. 5 is another side view of the mandrel of FIG. 3;

FIG. 6 is a bottom view of the mandrel of FIG. 3;

FIG. 7 is a partial elevational view, partially in crosssection, of the mandrel shown in FIGS. 3-6 used to fabricate the spindle of FIG. 2; and

FIG. 8 is a partial elevational view, partially in crosssection, taken to the view of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawing a roll type filter housing 10 is disclosed in vertical position. Housing 10 includes top filter medium supply section 1], central air treating section 12, and bottom filter medium rewind section 13. It is to be understood that a supply roll of filter medium can be mounted in wound form in supply section 1 1. This supply roll which can be comprised of a web'of any one of a number of known suitable filter medium materials is advanced incrementally from time to time into and through the central air treating section 12, which frames the air stream passage through which the air to be treated must flow. As the web is progressively advanced through central section 12, the web filters the contaminants from the air. The web is then correspondingly progressively advanced to the rewind section 13 where it is wound upon a spindle 14, into a discharge roll which can be'ultimately thrown away or reconditioned. Suitable drive motor and web metering controls known in the art (not shown) can be utilized to advance the medium progressively in the manner described above. i

As can be seen in FIG. 2 of the drawing, spindle 14 is comprisedof a tubular core 18 which can be made from any one of a number of suitably selected light weight fabricating metals. Advantageously, it is of generally circular cross-section. Tubular core 18 is provided with end plates 16 and 17 which are attached thereto by means of opposed mandrels 21 to form spindle 14. Fastened adjacent tubular core 18, having one turned end disposed in slot means 22 of end plate 16 and the other turned end disposed in slot means 23 in end plate 17, is web fastening means 24. Web fastening means 24 can'be fabricateil from any one of a number of known-flexible materials; advantageously a 9 guage steel wire is utilized. The web fastening means is secured to the respective end plates 16 and 17 by providing therein suitable slot means 22 and 23, through which the ends of web fastening means 24.may be in- 'serted after being turned at an angle of about 90 to the main body portion. In assembling spindle 14 it is simpliest to first place the ends of web fastening means 24 into their respective slot means on the end plates and then align that assembly with respect to tubular core 18 and finally insert mandrels 21 at opposite ends of core 18. Slot means 22 and 23 are preselectiv'ely located on end plates 16 and 17 and web fastening means 24 is so contoured and sized in length between its turned ends that when spindle 14 is assembled web fastening means 24 is adjacent to tubular member 18 and exerts a slight pressure at preselected locations thereon. It should be noted that consistent with this invention the end of the web is most simply secured to tubular member 18 by folding the sides of the web adjacent the end inwardly several times and inserting it in folded condition at the center of tubular core 18 and under web fastening means 24 and then spreading it along the length of tubular core 18 until its respective edges abutt end plates 16 and 17. It will be noticed that having preselectively positioned slot means 22 and 23 the web will be held against tubular core 18, and especially tightly at the edges thereof. Such an arrangement has been found to be advantageous in that it holds the web smooth and flat and provides for trouble free advancement thereof.

FIGS. 3 through 6 show one of the mandrels 21. As can be seen from those figures, mandrel 21 is tapered and of irregular cross-sectional shape thereby allowing it to be easily inserted into one end of tubular core 18 and to be positively frictionally held therein and capable of transmitting a torque to spindle 14. Mandrel 21 has at its smallest end, bevel 26 which functions to spread and open the end of tubular core 18, as said mandrel is inserted into tubular core 18. The gentle taper indicated along body portion 27 of mandrel 21 provides an ever increasing frictional force against the inner walls of tubular core 18 as mandrel 21 is further inserted therein. In addition, wing portions 28 are tapered to additionally enhance the frictional grip of mandrel 21. Also, located at the larger end of mandrel 21, is intermittent flange portion 29 which functions to secure an end plate to tubular member 18 as is shown in FIGS. 7 and 8.

Mandrel 21 also includes support and coupling shelf 31 located interior of the body portion 27 which serves to give mandrel 21 radial strength as well as provide a suitable coupling portion through which torque may be transmitted to accomplish rewinding of the filter web. Advantageously, flat portions 32 can be provided which even further enhance the effectiveness of the coupling function of mandrel 21.

Advantageously end plates 16 and 17 may each have an irregular hole concentrically positioned therein, which conforms to the shape of body portion 27 of the mandrel, and which can be appropriately aligned with the mandrel to allow the mandrel to be more easily inserted into one end of tubular core 18 in securing relationship with end plates 16and 17. More specifically, insertion of mandrel 21 causes an expansion of tubular core 18 which results in frictional forces securing the two members together and securing the end plate between flange 29 and the end of tubular core 18.

As can be seen from FIGS. 7 and 8 the provision of wing portions 28 results in considerably more stretching in one radialdirection than in a radial direction thereto, upon insertion of mandrel 21 into tubular core 18. The overall result is that the end of tubular member 18 assumes a generally elliptical cross-sectional configuration. This elliptical cross-section has been found to be most desirable for transmitting a torque to tubular member 18.

Having thus described the invention what is claimed 1. In an air cleaning device of a type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage from a supply zone to a rewind zone an improved spindle assembly for supporting and rewinding contaminant loaded media into a roll, said spindle assembly comprising: a substantially rigid hollow core of generally circular cross-section to provide a support upon which said web may be rewound, said core being arranged to extend transversely across the air cleaning device; end plates at each end of said core to manipulate said web into a roll, irregularly shaped mandrels inserted in each end of said core to securely fasten said end plates to said core and provide coupling means by which a torque may be transmitted to said spindle each of said mandrels being further defined as having a body portion of increasing taper thereby allowing it to be easily inserted into one end of said core, and being of irregular cross section, said body portion having at its smallest end a bevel of greater taper than the taper of said body portion which functions to spread open the end of said hollow core as said mandrel is inserted into said core, and diametrically opposed wing portions which are also tapered, thereby stretching said core to enhance the frictional forces between said mandrel and said core to give greater stretching of said core in one radial direction than in a radial direction 90 degrees thereto when said mandrel is inserted in said core.

2. The apparatus of claim 1 wherein said mandrel additionally comprises a support and coupling shelf interior of said body portion lying in substantially the same plane as the plane defined by said diametrically opposed wing portions to give additional radial strength to said mandrel and provide coupling means for the transmission of a torque to said spindle assembly.

3. The apparatus of claim 1 wherein said body portion of each of said mandrels additionally comprises diametrically opposed flat portions to enhance the frictional forces between said mandrels and said core.

4. The apparatus of claim 1 wherein said rigid hollow core is comprised of a light weight fabricating metal. 

1. In an air cleaning device of a type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage from a supply zone to a rewind zone an improved spindle assembly for supporting and rewinding contaminant loaded media into a roll, said spindle assembly comprising: a substantially rigid hollow core of generally circular cross-section to provide a support upon which said web may be rewound, said core being arranged to extend transversely across the air cleaning device; end plates at each end of said core to manipulate said web into a roll, irregularly shaped mandrels inserted in each end of said core to securely fasten said end plates to said core and provide coupling means by which a torque may be transmitted to said spindle each of said mandrels being further defined as having a body portion of increasing taper thereby allowIng it to be easily inserted into one end of said core, and being of irregular cross section, said body portion having at its smallest end a bevel of greater taper than the taper of said body portion which functions to spread open the end of said hollow core as said mandrel is inserted into said core, and diametrically opposed wing portions which are also tapered, thereby stretching said core to enhance the frictional forces between said mandrel and said core to give greater stretching of said core in one radial direction than in a radial direction 90 degrees thereto when said mandrel is inserted in said core.
 2. The apparatus of claim 1 wherein said mandrel additionally comprises a support and coupling shelf interior of said body portion lying in substantially the same plane as the plane defined by said diametrically opposed wing portions to give additional radial strength to said mandrel and provide coupling means for the transmission of a torque to said spindle assembly.
 3. The apparatus of claim 1 wherein said body portion of each of said mandrels additionally comprises diametrically opposed flat portions to enhance the frictional forces between said mandrels and said core.
 4. The apparatus of claim 1 wherein said rigid hollow core is comprised of a light weight fabricating metal. 